Field of the Invention
The present invention is directed to a Controlled Area Network (CAN) installed on a vehicle having an improved pumping system for pumping product. More specifically, embodiments of the present invention comprise centralized CAN-based control of various vehicle elements, including improved safety mechanisms. Embodiments of the present invention comprise an improvement in pump efficiency and control.
Description of the Related Art
Generally, the various embodiments of the present invention are applicable to a vehicle having the following core components: a truck chassis; a pressure vessel for storing product therein, e.g., in the case of a typical bobtail propane truck, well known to the skilled artisan, this may comprise a propane cargo tank, a product pump; a drive system for the product pump; piping from the product pump to a metering mechanism; piping from the metering mechanism to a hose reel; manual shutoff valve(s); a remote pump and valve shutoff system for controlling an emergency discharge; safety mechanisms, e.g., chock blocks for the wheels, proximity sensors for the piping outlets, emergency shut off switches and the like; a liquid level gauge; pressure gauges; a temperature gauge; and lighting.
The known vehicles comprising at least some of these listed components generally comprises a system of pressure switches, relays, wire harnesses, air lines, and drive lines, entirely lacking in integration of the various components in a centralized controller mechanism. Each known individual component or system, therefore, performs its function, but without communication capability to any of the other systems. Various problems result, not the least of which is the lack of integrational information related to the various safety mechanisms on the vehicles. As a result, these individual and unconnected systems operate independently and must therefore be individually and manually monitored.
In addition, known vehicles comprising a product pump system require the pump to operate only at a maximum speed, or at a finite set of individual and discrete speed points. As a general practice, known product pumping systems are not designed to intentionally vary the speed of the product pump because the pumps are sized and applied within a system for which the primary goal is maximization of pump efficiency. Instead, these known systems require selection of a pump speed which is then maintained during the operation.
In these cases, upon output requirements of the pumping system, a bypass loop is provided whereby product is diverted back to the reservoir or cargo tank. The diversion of product back to a reservoir or cargo tank is inefficient as it requires extra work to be done by the pump.
Moreover, known vehicles as discussed above require direct drive systems that demand that the vehicle engine idle at the slowest possible speed to ensure there is no detrimental effects to the product pump since the engine in these known systems is directly coupled to the product pump through the use of a “hot shift” power take-off (PTO), either “on” or “off”. This slow engine idle results in soot buildup in the vehicle engine that is detrimental to the engine and emission system, leading to premature failure.
Hydraulic systems are available for breaking the connection between the engine and the product pump, but these systems do not operate automatically based on the output of the components that the, hydraulic system drives. Instead, these known hydraulic systems are simply based on the allowance of different manually set individual and discrete points.
Further, known systems will comprise product pumps that will cavitate from time to time as a result of vapor in the pump. In order to ensure the cavitation state is not run for too long a period of time, known systems require that the product pump simply be shut down manually. Further, the notice of cavitation in known systems is provided by a pressure or flow meter that visually displays an abrupt reduction in output flow. Additionally, cavitation may be audibly noticeable to the operator. In all known cases, annunciation of cavitation requires an operator to manually shut the pump down. One other option for known systems running under a state of cavitation is to simply allow the product pump to continue cavitating; leading to damage to the product pump and shorter pump lifespan, as well as very inefficient and slowed delivery of product as the output flow is reduced as a result of the pump pumping vapor bubbles along with liquid or other content. All of the known systems require an operator to actively monitor for cavitation and, when noticed, the operator must take one of the above-mentioned steps in response. None of the known systems allow for automated monitoring of the cavitation problem as well as an automated adjustment of the pump speed in response until the cavitation-causing vapor problem has been resolved.
Finally, known pump systems require a manual adjustment of the output flow rate and, therefore, do not and cannot automatically adjust based on demand.
The present invention provides solutions for, inter alia, these problems.